1. Technical Field
The present disclosure of invention relates to liquid crystal displays (LCDs) and more particularly, to LCDs employing multi primary color matrixes.
2. Related Technology
In recent years, investigation has begun into LCD displays that utilize different primary colored and/or white light sources for their subpixel repeating group (the group of three or more differently colored subpixels and optionally one or more additional white subpixels that tessellate and thereby populate the display area). The combination of different primary colored and/or white lights may be used to increase the color gamut producible by the device as well as to increase the efficiency of the LCD panel in terms of power consumption. Such multi primary color displays may use differently colored light emitting diodes (LED's, including white light emitting ones) as their backlighting light sources. Such multi primary color displays may additionally, be configured for field sequential operation, in which each image frame is subdivided into a sequential displaying of two or more fields, where each of the sequential fields energizes only a subset of the total number of subpixels used by the frame. The energizing of the subpixels with different patterns over a temporal span covered by plural fields allows for display resolution enhancing schemes such as those that rely on over-time light integration by the human visual system and/or those that rely on across-location (spatial) light integration by the human visual system.
Heretofore, it was common practice to employ at least three, if not more, fields per frame when using multi primary color displays. Some of such deployments may have included use of local backlight dimming in which the light sourcing blocks are selectively dimmed or brightened in conjunction with setting the grayscale levels of their respective light-passage controlling (light valving), liquid crystal cells. However, under current liquid crystal technologies, including those that use reduced switching rates (e.g., to reduce power consumption), a field sequential operation with at least three to four fields per frame may introduce flicker and other undesired artifacts such as color break artifacts.
Some of these drawbacks may be overcome by switching back to operating at relatively high field update rates (e.g., more than 500 fields per second), but such increase in switching rate would disadvantageously increase power consumption. Additionally, since the liquid crystal re-orientation time of liquid crystal cells is often relatively long compared to the field update time at such relatively high field update rates, undesirable color mixing may occur and this poses a major problem. It is possible to address this last point by energizing (flashing) the backlight LEDs only for short periods of time at the end of the respective field update periods, but this disadvantageously reduces the LEDs' efficiency and may require a very large number of LEDs for achieving an acceptable luminance which in turn disadvantageously increases the size and power consumption of the display. Therefore it seems that advancements for the multi primary color matrix approach may be at their end due to an irresolvable tradeoff problem that pits power consumption against production of undesirable image artifacts.
It is to be understood that this background of the technology section is intended to provide useful background for understanding the here disclosed technology and as such, the technology background section may include ideas, concepts or recognitions that were not part of what was known or appreciated by those skilled in the pertinent art prior to corresponding invention dates of subject matter disclosed herein.